// 2025/4/19
// 判断是不是平衡二叉树

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 *	TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 * };
 */
class Solution {
    public:
        /**
         * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
         *
         * 
         * @param pRoot TreeNode类 
         * @return bool布尔型
         */
        int getHeight(TreeNode* root)
        {
            if(root == nullptr)
                return 0;
            
            int left = getHeight(root->left);
            int right = getHeight(root->right);
            if(left == -1 || right == -1)
                return -1;
            if(left > right + 1 || right > left + 1)
                return -1;
            return max(left, right) + 1;
        }
    
        bool IsBalanced_Solution(TreeNode* pRoot) {
            // write code here
            if(pRoot == nullptr)
                return true;
            int left = getHeight(pRoot->left);
            int right = getHeight(pRoot->right);
            if(left == -1 || right == -1)
                return false;
            if(left > right + 1 || right > left + 1)
                return false;
            return true;
        }
    };